I have a question about the front shock. I've picked up a low mileage Tesi 3D and I'm going through the bike before I ride it. It seems the front end has some sag when sitting with no rider and I wanted to know if the shock uses air or nitrogen. The manual says 9.5 Bar of Air is standard. Thanks for any help on this.

nitrogen does not contain the moisture and other contaminants found in compressed air so, as you drive and the shock heat up, nitrogen filled shocks will fluctuate less in temperature and pressure than air filled while driving. The bottom line is, you will still see pressure changes with nitrogen but, overall, your shock will run cooler and at a more consistent pressure than if they were filled with air.

And now some NASCAR info on the 2

NASCAR Information

Fundamentally; air, oxygen and nitrogen will all behave exactly the same in terms of pressure change for each 10 degrees of temperature change. However temperature alone is not the whole story.

Ambient air contains moisture, nitrogen does not. If moisture is present it contributes to a greater change in pressure simply because at lower temperatures water condenses to become a liquid. The liquid form of water occupies very little volume and contributes only a negligible pressure to the tire. But at higher temperatures, such as those in a running tire, water evaporates inside the tire and becomes a gas which increases pressure in the tire.

Ambient air contains about 21% oxygen. Oxygen’s smaller molecular size allows it to permeate through the rubber of the tire. By inflating with nitrogen, which is much less permeable than oxygen, the pressure changes due to oxygen loss are greatly reduced.

The racing industry is correct; nitrogen is more predictable. Because nitrogen is dry it has no moisture to contribute extra pressure changes with temperature. Because nitrogen permeates out much slower than oxygen pressure changes due to that leakage are almost eliminated compared with ambient air.

What I dont know though...is what is used in the manufacture process...what Shock is on the bike? Manufacturer and model? The technical depts of the company should be able to help.....

I have a mountain bike with a FOX Vanilla Float air only system...separate HP connector...that I merely pump to correct pressure with air....but its merely a mountain bike and not a Tesi Bimota

Is it fitted with a "pull rod Extreme Tech" Unit??

I've tied several times before to "find" the company.....but being italian its difficult....as theres also a US software company by the same name...this company sells their gear so you could try and ask them....or email Bimota directly?

Email contact addresses contained above....they mention Bimota...as their shocks are used on DB5/6/7/8/9/10 and the Tesi.....so ask them the question...maybe in English and Italian (use Google Translate)

No worries.....next effort would be to Bimota if no answer (Italian companies are reknowned for ignoring anythiing and anyone not from Italy)....I presume you can at least link a tyre pressure gauge to it to check the pressure as is? Would give you a reference whether its low or not.....The Extreme Shox manuals do seem to indicate checking the pressure before every ride...which sounds Extreme in itself

Jbuffa,
I tried to find out if there was a tool for adjusting the preload on the rear shock but got nowhere so will you let us know how you go? There has been some previous discussion on the high pressure for the front shock but I çouldn't find it and I'm not sure which forum it was on but I will keep looking.
Ian

Jbuffa,
I tried to find out if there was a tool for adjusting the preload on the rear shock but got nowhere so will you let us know how you go? There has been some previous discussion on the high pressure for the front shock but I çouldn't find it and I'm not sure which forum it was on but I will keep looking.
Ian

What type of rear shock do you have? If its the extreme Tech Upgrade shock with red anodised remote body and gold locking ring ...its easy....one of the holes on the outside of the locking ring has an allen key grub screw that you unfasten....it locks on the thread of the main body...then I use a small flat blade screwdrive...short shaft...where the shaft is just smaller than the diameter of the hole...and use this as a lever to rotate the locking ring to adjust the preload....evidently when happy....retighten the allen key locking screw

Well I was finally able to put together a Nitrogen rig to charge my front shock properly. I'll have to revisit my riding impressions of the Tesi because when I put a proper gauge on the shock, I had only 87 PSI (originally I used a friends gauge that was pretty old and must have been dropped or abused). The manual calls for 137 PSI as the Standard setting. Just with a push test in the garage it felt harder, but the main thing was the rebound was much more responsive. I'll be riding on Wednesday when the weather let's up here in Atlanta. It did feel as if the front end was a bit droopy but I've never ridden a Hub steering bike before. I think it should ride much better now.